11. x = 10, so DCE is 72. You get the measurement of x by adding 7x + 2 and x + 8 to equal 90. When you get x, you plug it in to the equation for DCE.
12. x = 17. KNM is 131. Get the measurement of x by adding both equations again, this time equaling it to 180 since it is a straight line and doesn't have a right angle. Plug in the x to the equation for KNM.
